Commerce Secretary Wilbur Ross has a financial stake in a shipping firm that does business with a gas producer partly owned by a Russian oligarch and the son-in-law of President Vladimir Putin, according to a report on Sunday.

Ross, a billionaire banker and investor, through a number of partnerships owns a 31 percent of Navigator Holdings, a shipping company that transports materials for Sibur, a Russian gas and petrochemical producer, the New York Times reported.

Kirill Shamalov, who is married to Putin’s youngest daughter, and Gennady Timchenko, a close friend and judo partner of the Kremlin leader, are the top owners of Sibur, the Times reported, citing documents obtained by the International Consortium of Journalists.

Ross’ investment in Navigator comes even as the United States and the European Union imposed economic sanctions against Moscow — including its gas industry — for the country’s incursion into Crimea in 2014.

The report said Ross sold off many of his holdings after President Trump named him Commerce Secretary as he led the administration’s “America First” trade policy.

But he kept his investment with Navigator, valued at between $2 million and $10 million, through a chain of companies in the Cayman Islands, a noted tax haven.

In his public ethics disclosures filed in January, Ross included the partnerships he intended to remain involved with, but did not mention which companies they invested in.

He mentioned his connection to Navigator in a description of his holdings ending in December 2016, but did not indicate any ties to Sibur, the report said.

​Trump’s former campaign manager, Paul Manafort, and his longtime business associate, Rick Gates, were indicted by the Mueller team last Monday on charges of conspiracy against the United States, tax fraud and money laundering.

The indictment said the two secretly funneled millions of dollars into the United States while working for a pro-Russian politician in Ukraine. ​